/**
 * plugin.js
 *
 * Released under LGPL License.
 * Copyright (c) 1999-2015 Ephox Corp. All rights reserved
 *
 * License: http://www.tinymce.com/license
 * Contributing: http://www.tinymce.com/contributing
 */

/*global tinymce:true */

tinymce.PluginManager.add('tabfocus', function (editor) {
    var DOM = tinymce.DOM, each = tinymce.each, explode = tinymce.explode;

    function tabCancel(e) {
        if (e.keyCode === 9 && !e.ctrlKey && !e.altKey && !e.metaKey) {
            e.preventDefault();
        }
    }

    function tabHandler(e) {
        var x, el, v, i;

        if (e.keyCode !== 9 || e.ctrlKey || e.altKey || e.metaKey || e.isDefaultPrevented()) {
            return;
        }

        function find(direction) {
            el = DOM.select(':input:enabled,*[tabindex]:not(iframe)');

            function canSelectRecursive(e) {
                return e.nodeName === "BODY" || (e.type != 'hidden' &&
                    e.style.display != "none" &&
                    e.style.visibility != "hidden" && canSelectRecursive(e.parentNode));
            }

            function canSelect(el) {
                return /INPUT|TEXTAREA|BUTTON/.test(el.tagName) && tinymce.get(e.id) && el.tabIndex != -1 && canSelectRecursive(el);
            }

            each(el, function (e, i) {
                if (e.id == editor.id) {
                    x = i;
                    return false;
                }
            });
            if (direction > 0) {
                for (i = x + 1; i < el.length; i++) {
                    if (canSelect(el[i])) {
                        return el[i];
                    }
                }
            } else {
                for (i = x - 1; i >= 0; i--) {
                    if (canSelect(el[i])) {
                        return el[i];
                    }
                }
            }

            return null;
        }

        v = explode(editor.getParam('tab_focus', editor.getParam('tabfocus_elements', ':prev,:next')));

        if (v.length == 1) {
            v[1] = v[0];
            v[0] = ':prev';
        }

        // Find element to focus
        if (e.shiftKey) {
            if (v[0] == ':prev') {
                el = find(-1);
            } else {
                el = DOM.get(v[0]);
            }
        } else {
            if (v[1] == ':next') {
                el = find(1);
            } else {
                el = DOM.get(v[1]);
            }
        }

        if (el) {
            var focusEditor = tinymce.get(el.id || el.name);

            if (el.id && focusEditor) {
                focusEditor.focus();
            } else {
                tinymce.util.Delay.setTimeout(function () {
                    if (!tinymce.Env.webkit) {
                        window.focus();
                    }

                    el.focus();
                }, 10);
            }

            e.preventDefault();
        }
    }

    editor.on('init', function () {
        if (editor.inline) {
            // Remove default tabIndex in inline mode
            tinymce.DOM.setAttrib(editor.getBody(), 'tabIndex', null);
        }

        editor.on('keyup', tabCancel);

        if (tinymce.Env.gecko) {
            editor.on('keypress keydown', tabHandler);
        } else {
            editor.on('keydown', tabHandler);
        }
    });
});
